No, they're buying Android phones for just about every other reason (approx 80% marketshare according to IDC [1])
[1] http://www.businessinsider.com/iphone-v-android-market-share...
You cannot really compare something sold in 200 models and 50 price points to something sold in 5 models and 5 price points. It will be like saying people buy more Toyotas than Mercedes. Well, of course they do.
Here's another data point: this 80% of marketshare is reversed when considering profits.
Actually, not true. iOS only controls about 52.7% of the revenue share -- however Android has been creeping up every quarter and now places like Forbes and BusinessInsider are predicting Android will overtake iOS in revenue share in not too long.[1]
[1] http://www.businessinsider.com/apple-revenue-android-2014-4